The present invention relates generally to radiant floor heating systems and the manner in which they are installed. More specifically, the present invention relates to a router guide system that is used for cutting the necessary tubing return bends into solid flooring underlayment panels such that the return bends are aligned with the grooves in traditional, pre-grooved radiant flooring underlayment panels.
As homebuilding technology has improved over the past several years, building contractors have sought out newer technologies that are both cost effective while also serving to make the occupant of the completed building more comfortable. In this context, radiant floor heating systems have become an extremely popular method for the delivery of heat in both commercial buildings and residential homes. Radiant floor heating systems are similar in operation to older forced hot water baseboard systems where warm water is pumped through an array of pipes to distribute heat. The main difference between the two systems is that the older base board systems distributed the warm water through an array of miniature radiant panels connected by rigid piping and arranged along the exterior walls of the building, while radiant floor heating systems pump warm water through flexible cross-linked polyethylene plastic pipe, known as PEX, which is installed directly under the finished floor.
When radiant heating systems were first introduced, the plastic warm water distribution pipes were commonly imbedded in concrete floors or stapled to the underside of the sub-floor sheathing (staple-up method). However, as the radiant floor systems became more popular, several radiant pipe manufacturers began to develop proprietary underlayment panels, such as those depicted in FIG. 1, which could be installed directly onto floor joists in new construction, or over existing concrete or plywood sub-flooring. Typically, these prior art underlayment panels 2 are made of ½ inch or ¾ inch CDX plywood and are attached to an aluminum backing that acts as a heat spreader to more evenly distribute the heat throughout the finished floor. The panels 2 come in various sizes, such as for example 7×48 inches and 10×48 inches. Regardless of size, each panel 2 has a groove 4 down the center of the plywood panel 2 to accept a single run of tubing 6, so when the panels 2 are installed side-by-side onto the floor, the tubing 6 runs end up being spaced apart at either 7 inches or 10 inches on-center, depending on the width of the panel 2. In addition, some panels 2 have narrow grooves 4 therein for use with smaller ¼ inch (I.D.) tubing, while others have grooves 4 that are suited to more typical ⅜ inch or ½ inch tubing. Once the panels 2 are installed, the tubing 6 is then installed into the grooves 4 and retained in place by frictional force.
While the above noted panels 2 work well in straight line tubing runs, since the tubing loop for any given installation needs to be continuous and unbroken from beginning to end, it is necessary that the tubing be looped back into an adjacent groove at the end of each straight line run. To facilitate the looping back of the tubing 6 at the end of each run, the underlayment manufacturers also sell panels that include U-shaped return grooves to receive tubing bends for use at the end of each straight line run. These panels 8, sometimes called “filler strips” or “return panels”, permit the installers to turn the tubing 6 180-degrees back through a semi-circular arc and into an adjacent groove 4 so that the tubing 6 can run back and forth across the floor.
While these underlayment panel systems have significantly shortened installation time as compared to the older staple-up or embedded concrete installation methods, they have also created several new design and installation problems of their own. The first issue is that the design of the system and the layout of the panels and returns requires a detailed piping plan that is well thought out in advance. This is particularly important because the installer must leave proper room for the return panels at each end of the room and must know the location of these return panels in advance. Further, while the underlayment panels are rectangular in shape, making them easy to layout and install in a square or rectangular room, when the panels are installed into an odd-shaped room that has walls arranged at other than 90-degree angles as is depicted in FIG. 2, the design work becomes even more critical. In these installations, the return panels 8 must be cut and staggered across the non-square wall. Then additional filler panel material 10 must be installed into the voids around the staggered return panel 8 sections. Finally, it is important that the installer carefully align the groove in the return panels with the grooves in the adjacent underlayment panels because if they are not aligned as seen at 12 in FIG. 1, tubing installation becomes very difficult.
Accordingly, there is a perceived need in the radiant floor heating industry for an improved system for the installation of return panels. Further, there is a perceived need for a method or technique of creating the return bends in place such that non-rectangular room geometries can be accommodated. Still further, there is a perceived need for a method or technique of creating the return bends in place such that the grooves in the return bends are perfectly aligned with the grooves in the underlayment panels.